The present disclosure relates to an image processing apparatus. In detail, it relates to an image processing apparatus and an image processing method which detects a moving photographic subject included in an image, and a program which causes a computer to execute this method.
In recent years, image processing apparatuses have become widespread, such as digital still cameras and digital video cameras (for example, camera-integrated recorders) which generate an image (image data) by capturing a photographic subject such as a person or an animal, and record this image (image data) as image content.
Here, for example, in the case where an imaging operation is performed for a scene with a large difference of brightness and darkness, it is assumed that the dynamic range of an image sensor included in an image processing apparatus will be insufficient. In the case where the dynamic range of such an image sensor is insufficient, for example, over-exposure will often occur by a bright portion being saturated in an image generated by the imaging operation.
Accordingly, an image processing apparatus has been proposed which generates a combined image in which the dynamic range is enhanced, by combining a long time exposure image and a short time exposure image generated by an imaging operation during different exposure times. However, in the case where a moving photographic subject (a photographic subject which is moving) is included in the images used for the generation of a combined image, there is the possibility that false color, noise or the like will occur in the region of the moving photographic subject, and the quality of the image will be reduced.
Accordingly, for example, an image processing apparatus has been proposed which acquires a pixel value difference of a plurality of combined images, performs a comparison between this pixel value difference and a predetermined threshold, and estimates a region in which the pixel value difference is at or above the threshold as a moving photographic subject region (for example, refer to JP 2011-87269A).